Work machines such as, for example, motor graders, backhoe loaders, agricultural tractors, wheel loaders, skid-steer loaders, and other types of heavy machinery are used for a variety of tasks requiring operator control of the work machine and various work implements associated with the work machine. These work machines and work implements can be relatively complicated and difficult to operate. They may have an operator interface with numerous controls for steering, position, orientation, transmission gear ratio, and travel speed of the work machine, as well as position, orientation, depth, width, and angle of the work implement.
Historically, work machines have incorporated single-axis lever control mechanisms with complex mechanical linkages and multiple operating joints, or a plurality of cables to provide the desired functionality. Such control mechanisms require operators with high skill levels to control the many input devices. After a period of operating these control mechanisms, the operators may become fatigued. In addition, because an operator's hand may be required to travel from one actuating element to another, an operator's delayed reaction time and the complexity and counter-intuitiveness of the controls may result in poor quality and/or low production.
An operator interface may include a joystick control system designed to reduce operator fatigue, improve response time of the operator, and improve results of the work machine. For example, U.S. Pat. No. 5,042,314 (the '314 patent) issued to Rytter et al. on Aug. 27, 1991, describes a steering and transmission shifting control mechanism that includes a transversally rockable control handle. The steering and transmission shifting control mechanism also includes a steering actuator element connected at the bottom of the control handle to depress either a left or right actuating plunger of a hydraulic pilot valve assembly for effecting steering. The steering and transmission shifting control mechanism further includes an electrical switch activating element to change the speed of a multi-speed transmission through an associated electronic control system.
Although the steering and transmission shifting control mechanism of the '314 patent may alleviate some of the problems associated with separate work machine controls for effecting steering and transmission operations, the steering and transmission shifting control mechanism may not control enough of the features and/or functions of the work machine and work implement to reduce operator fatigue and improve the quality and/or production of the work machine. An operator may still be required to operate multiple control devices to effect articulation, wheel tilt, work implement position and orientation control, throttle control, alignment control, differential control, and other work machine and implement functions and features. In addition, the steering and transmission operations of the steering and transmission shifting control mechanism of the '314 patent may still require operator input that is complex or counter-intuitive.
The disclosed control system is directed towards overcoming one or more of the problems as set forth above.